Boston city councilors and administration leaders began to bid farewell to long-serving Mayor Thomas M. Menino as he announced this will be his last year in office.

“We’re all a little shocked,” City Councilor Matthew O’Malley said. “This is a guy who has been mayor since I was in the eighth grade.”

“I’ve learned so much from Mayor Menino in the last seven years,” Police Commissioner Edward F. Davis said. “The city loses a guy who was a great leader and urban fixer.”

A closed-door gathering, held on City Hall’s fifth-floor office yesterday, included a mix of tears and laughter, attendees said.

“I think it’s hard for people to know how to react because he has been mayor for 20 years,” one official said. “I am hearing some people saying they are sad for the mayor and other people saying they are happy for the mayor. He has done a great job and has gone through an awful lot physically. He’s now going out on the top of his game.”